All categories

3 years ago

WWhat do these substances have in common?

Chemistry

2 answers:

olga2289 [7]3 years ago

8 0

Answer; Option A is correct

Explanation:

Matter is substance which is made up of atoms
Matter is a substance which occupies physical space

All the given four substance are matter :

Apple juice is a mixture.

Helium gas is a pure substance.

Salt water is mixture.

Copper wire is a pure substance.

But all of them are composed of atoms.

Mariana [72]3 years ago

4 0

The answer is that they are Pure substances

You might be interested in

____ 26. what is the weight percentage of nitrogen in urea, cn2h4o

Paraphin [41]

Weight percentage of nitrogen can be calculated using the following rule:
weight percentage of nitrogen = (weight of nitrogen / weight of urea) x 100

From the periodic table:
molecular mass of carbon = 12 grams
molecular mass of nitrogen = 14 grams
molecular mass of hydrogen = 1 grams
molecular mass of oxygen = 16 grams

therefore:
mass of nitrogen in urea = 2(14) = 28 grams
mass of urea = 12 + 2(14) + 4(1) + 16 = 60 grams

Substitute with the masses in the equation to get the percentage:
weight percentage of nitrogen = (28/60) x 100 = 46.667%

7 0

4 years ago

Under identical conditions, separate samples of O2 and an unknown gas were allowed to effuse through identical membranes simulta

Brut [27]

Answer:

The molar mass of unknown gas is 145.82 g/mol.

Explanation:

Volume of oxygen gas effused under time t = 8.24 mL

Effusion rate of oxygen gas = $R=\frac{8.24 mL}{t}$

Molar mass of oxygen gas = 32 g/mol

Volume of unknown gas effused under time t = 3.86 mL

Effusion rate of unknown gas = $R'=\frac{3.86 mL}{t}$

Molar mass of unknown gas = M

Graham's Law states that the rate of effusion or diffusion of gas is inversely proportional to the square root of the molar mass of the gas. The equation given by this law follows the equation:

$\text{Rate of diffusion}\propto \frac{1}{\sqrt{\text{Molar mass of the gas}}}$

$\frac{R}{R'}=\sqrt{\frac{M}{32 g/mol}}$

$\frac{\frac{8.24 mL}{t}}{\frac{3.86 mL}{t}}=\sqrt{\frac{M}{32 g/mol}}$

$M=\frac{32 g/mol\times 8.24 \times 8.24}{3.86\times 3.86}=145.82 g/mol$

4 0

3 years ago

PLEASE ANSWER ASAP 30PTS<br><br> How can you determine and object’s mechanical energy ?

pychu [463]

Mechanical energy of a body is simply the combination of its kinetic energy and potential energy

3 0

3 years ago

Which is the first stage of mitosis? Group of answer choices Anaphase Prophase Metaphase Telophase

ss7ja [257]

Answer:Prophase is the first stage of mitosis. In prophase,

Explanation:

3 0

3 years ago

Read 2 more answers

Which of the following substances has been determined to pose the most significant potential threat to human health in terms of

qwelly [4]

Answer:

Polycyclic aromatic hydrocarbons (from petroleum)

Explanation:

Polycyclic aromatic hydrocarbons (PAH) is a group of compounds which contain more than one aromatic ring. Typically examples include; naphthalene, anthracene, phenanthrene etc.

PAH are present in petroleum products. Almost everyone is regularly exposed to vehicles or other equipments that uses petroleum products as fuel. PAH is usually released from the combustion engine of these equipments and may be inhaled by humans. Thus there is a very high risk of PAH exposure compared to other items listed in the question.

PAHs are known to cause different kinds of cancer and other types of health issues in the body. The most disturbing toxicity of PAH is its carcinogenicity which makes it a very serious potential health risk for humans exposed to it on regular basis.

6 0

3 years ago